Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

A giant γ-ray flare from the magnetar SGR 1806–20

Abstract

Two classes of rotating neutron stars—soft γ-ray repeaters (SGRs) and anomalous X-ray pulsars—are magnetars1, whose X-ray emission is powered by a very strong magnetic field (B ≈ 1015 G). SGRs occasionally become ‘active’, producing many short X-ray bursts. Extremely rarely, an SGR emits a giant flare with a total energy about a thousand times higher than in a typical burst2,3,4. Here we report that SGR 1806–20 emitted a giant flare on 27 December 2004. The total (isotropic) flare energy is 2 × 1046 erg, which is about a hundred times higher than the other two previously observed giant flares. The energy release probably occurred during a catastrophic reconfiguration of the neutron star's magnetic field. If the event had occurred at a larger distance, but within 40 megaparsecs, it would have resembled a short, hard γ-ray burst, suggesting that flares from extragalactic SGRs may form a subclass of such bursts.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: The SGR spike and tail light curve from BAT on Swift.
Figure 2: The pulse profile evolution of the magnetar SGR 1806–20 during the giant flare of 27 December 2004.

References

  1. 1

    Thompson, C. & Duncan, R. C. The soft gamma repeaters as very strongly magnetized neutron stars. I. Radiative mechanism for outbursts. Mon. Not. R. Astron. Soc. 275, 255–300 (1995)

    ADS  Article  Google Scholar 

  2. 2

    Mazets, E. P., Golenetskii, S. V., Ilinskii, V. N., Apetkar, R. L. & Guryan, Y. A. Observations of a flaring X-ray pulsar in Dorado. Nature 282, 587–589 (1979)

    ADS  Article  Google Scholar 

  3. 3

    Fenimore, E. E., Klebesadel, R. W. & Laros, J. G. The 1979 March 5 gamma-ray transient: was it a classic gamma-ray burst? Astrophys. J. 460, 964–975 (1996)

    ADS  Article  Google Scholar 

  4. 4

    Hurley, K. et al. A giant periodic flare from the soft gamma-ray repeater SGR 1900 + 14. Nature 397, 41–43 (1999)

    ADS  MathSciNet  CAS  Article  Google Scholar 

  5. 5

    Hurley, K. et al. Reactivation and precise interplanetary network localization of the soft gamma repeater SGR 1900 + 14. Astrophys. J. 510, L107–L109 (1999)

    ADS  Article  Google Scholar 

  6. 6

    Woods, P. M. et al. Gradual brightening of SGR 1806 - 20. Astron. Telegr. 313 (2004)

  7. 7

    Gehrels, N. et al. The SWIFT gamma-ray burst mission. Astrophys. J. 611, 1005–1020 (2004)

    ADS  CAS  Article  Google Scholar 

  8. 8

    Borkowski, D. et al. Giant flare from SGR 1806 - 20 detected by INTEGRAL. GCN Circ. 2920 (2004)

  9. 9

    Palmer, D. M. et al. SGR1806 - 20: Swift-BAT observation of the 041227 super-flare. GCN Circ. 2925 (2004)

  10. 10

    Hurley, K. et al. An exceptionally bright flare from SGR1806 - 20 and the origins of short-duration γ-ray bursts. Nature doi:10.1038/nature03519 (this issue)

  11. 11

    Barthelmy, S. D. Burst Alert Telescope (BAT) on the Swift MIDEX mission. SPIE 5165, 175–189 (2004)

    ADS  Google Scholar 

  12. 12

    Belian, R. D., Gisler, G. R., Cayton, T. & Christensen, R. High-Z energetic particles at geosynchronous orbit during the great solar proton event series of October 1989. J. Geophys. Res. 97(A11), 16897–16906 (1992)

    ADS  Article  Google Scholar 

  13. 13

    Meier, M. M. et al. in the Proc. Workshop on the Earth's Trapped Particle Environment, AIP Conf. Proc. 383, 203–210 AIP Press, Woodbury, New York (1996).

  14. 14

    Kouveliotou, C. et al. Identification of two classes of gamma-ray bursts. Astrophys. J. 413, L101–L104 (1993)

    ADS  CAS  Article  Google Scholar 

  15. 15

    Corbel, S. & Eikenberry, S. S. The connection between W31, SGR 1806 - 20, and LBV 1806 - 20: Distance, extinction, and structure. Astron. Astrophys. 419, 191–201 (2004)

    ADS  CAS  Article  Google Scholar 

  16. 16

    Gaensler, B. M. et al. An expanding radio nebula produced by a giant flare from the magnetar SGR 1806 - 20. Nature doi:10.1038/nature03498 (this issue)

  17. 17

    Thompson, C. & Duncan, R. C. The giant flare of 1998 August 27 from SGR 1900 + 14. II. Radiative mechanism and physical constraints on the source. Astrophys. J. 561, 980–1005 (2001)

    ADS  Article  Google Scholar 

  18. 18

    Woods, P. M. et al. Large torque variations in two soft gamma repeaters. Astrophys. J. 576, 381–390 (2002)

    ADS  Article  Google Scholar 

  19. 19

    Woods, P. M. et al. Spin and pulsed X-ray flux properties of SGR 1806 - 20 after the giant flare. Astron. Telegr. 407 (2005)

  20. 20

    Woods, P. M. et al. Variable spin down in the soft gamma repeater SGR 1900 + 14 and correlations with burst activity. Astrophys. J. 524, L55–L58 (1999)

    ADS  CAS  Article  Google Scholar 

  21. 21

    Kennicutt, R. C. Jr The star formation law in galactic disks. Astrophys. J. 344, 685–703 (1989)

    ADS  CAS  Article  Google Scholar 

  22. 22

    Gallego, J., Zamorano, J., Aragon-Salamanca, A. & Rego, M. The current star formation rate of the local universe. Astrophys. J. 455, L1 (1995)

    ADS  CAS  Article  Google Scholar 

  23. 23

    Eichler, D. Waiting for the Big One: a new class of soft gamma-ray repeater outbursts? Mon. Not. R. Astron. Soc. 335, 883–886 (2002)

    ADS  Article  Google Scholar 

  24. 24

    Feroci, M., Hurley, K., Duncan, R. C. & Thompson, C. The giant flare of 1998 August 27 from SGR 1900 + 14 I. An interpretive study of BeppoSAX and Ulysses observations. Astrophys. J. 549, 1021–1038 (2001)

    ADS  Article  Google Scholar 

Download references

Acknowledgements

We acknowledge support from NASA (P.M.W., E.R.-R., B.M.G.); the German-Israeli Foundation (Y.E.L.); the NWO (R.A.M.J.W.); the DOE (J.G.); and the Israel-US BSF, the Israel Science Foundation, and the Arnow Chair of Theoretical Physics (D.E.).

Author information

Affiliations

Authors

Corresponding author

Correspondence to D. M. Palmer.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Supplementary information

Supplementary Figures S1-S3

Supplementary Figure S1, spike and tail time history, 64 ms resolution; Supplementary Figure S2, High resolution spike time history, 1 ms resolution; Supplementary Figure S3, SOPA spectrum of the main spike. (PDF 128 kb)

Supplementary Methods

A description of the use of SOPA and ESP to determine spike fluence, the use of BAT to determine tail fluence, and deadtime correction for BAT, and its limitations. (PDF 97 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Palmer, D., Barthelmy, S., Gehrels, N. et al. A giant γ-ray flare from the magnetar SGR 1806–20. Nature 434, 1107–1109 (2005). https://doi.org/10.1038/nature03525

Download citation

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing